1. Priority Claim
This application claims the benefit of priority from European Patent Application No. 06 014256.9, filed Jul. 10, 2006, which is incorporated by reference.
2. Technical Field
This disclosure relates to noise reduction. In particular, this disclosure relates to reduction of background noise in a hands-free vehicle communication system.
3. Related Art
The voice quality of vehicle communication systems, such as wireless telephone systems, may be degraded by background noise. Spectral subtraction circuits have been used to reduce noise, but are limited to processing stationary noise perturbations and positive signal-to-noise distances.
Microphone arrays and fixed beamforming techniques have also been used to improve the quality of transmitted speech. However, use of multiple microphones or microphone arrays may be limited by spatial restrictions and cost considerations. To reduce broadband noise, a reference signal should be detected close to the source of the primary signal. However, additional reference microphones placed near the primary signal source necessarily detect portions of the desired speech signal, causing distortion and damping of the audio speech signal.
Existing hands-free communication systems in vehicle environments do not provide adequate background noise reduction. Therefore, a need exists for a background noise reduction system that reduces background noise in a vehicle environment.